Gear check will be available at Boston Common.

In an email sent to runners, the B.A.A. wrote, “No bags will be allowed on buses from Boston to Hopkinton, and bags will not be transported from Hopkinton back to Boston. Bags will not be allowed in certain areas at or near the start in Hopkinton, at or near the finish in Boston, or along the course.”

The email stated the B.A.A. will provide a Heatsheet Warmth Rentention Cape at the conclusion of the race.

Runners will have the opportunity to check gear on Boston Common the morning of the marathon. Runners will receive a bag to be used for gear check when they pick up their race number. No other bags will be accepted.

Runners will also be allowed to wear additional layers of colthing on the shuttle buses and in Hopkinton for warmth before the race. Clothing not worn during the race must be discarded in Hopkinton and will be donated to a local charity.

The email also pointed out a few changes to the finish area for this year’s marathon. There will be three secure exit locations prior to Arlington Street. Runners who choose to take advantage of the gear check opportunity will have to walk approximately a half mile to receive their bag.

The B.A.A. also laid out items that will not be allowed in any "Marathon venue, including the course, Athlete's Village near the start in Hopkinton, start or finish area, and all officially-sanctioned Marathon events."

The list included: Backpacks, any similar item carried over the shoulder, or handbag of any size; glass containers; any container capable of carrying more than 1 liter of liquid; strollers, including baby strollers; suitcases and rolling bags; personal hydration system products (such as CamelBak, Thor, etc.); weight vest or any sort of vest with pockets (lightweight running vest are allowable); costumes covering the face or any non-form fitting, bulky outfits extending beyond the perimeter of the body; props (including sporting equipment and military and fire/gear and signs or flags larger than 11 inches x 17 inches); any items larger than 5 inches x 15 inches x 5 inches.

The email also stated the B.A.A. will prohibit unauthorized participants from taking part in the race. “We ask official participants to discourage family and friends who are not official registered participants from entering the course in any manner.

"We understand that many people want to participate in some way in this year's Boston Marathon as a display of support, but we ask that those who are not official participants to refrain from entering the course for the safety of runners and themselves."